Column thermostating devices

The earlier investigations employed several different types of plexiglas constructions containing the immobilized enzyme column. These devices were thermostated in a water bath, and the temperature at the point of exit from the column was monitored with a thermistor connected to a commercial Wheatstone bridge. The latter was constructed for general temperature measurements and osmometry. Later, we developed more sensitive instruments for temperature monitoring indigenously the water bath was replaced by a carefully temperature-controlled metal block, which contained the enzyme column. The enzyme thermistor concept has been patented in several major countries. 

For this purpose, mainly two thermostating devices are applied air-bath thermostats and liquid thermostating using jacketed columns. In all systems, the temperature stability, adjustable temperature range and heat capacity are important considerations. For air-bath thermostats, the shape and capacity of the oven, the ease of column installation and safety aspects are additional factors. 

This method is the most widely used because it gives a good picture of batch reactions performed in industry. Reactions are carried out in a thermostated flask fitted with constant speed stirrer, inert gaz inlet, sampling device, thermometer, distillation column, and condenser. 

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